Obviously you should be thrilled having just one acceptance, but the ultimate goal is to have a choice between great schools. Yea this will also add a new stress - choosing. Once again, you are liable to find many varying opinions on how to choose. The only real advice is to figure this out on your own.
Bring up the wordprocessor, use excel, write on paper, ect. Put down the pros and cons of every school. Some examples include tuition, class size, match-rate, board scores, location, ect. Figure out what you want.
I got into three schools and the choice was not simple. In the end, UIC simply was the best choice for me. I like having every specialty in house. I went to undergrad in a very rural area..so a move to the city (and closer to home) felt right. Oh yea, in-state tuition is also a major plus. If I had gone out of state, I would have essentially doubled my debt. I know everyone thinks dentists make a lot of bling. Let me ask you this, how many 27 year old dentists do you know? Most of them are not running private practices that is for sure, so even clearing 100k out of school is unlikely for freshly minted docs. It takes a few years to really get root into a community. But I digress...
You usually have a good month or so before that first deposit is due. I would not recommend laying down more than one because the choice does not get any easier by delaying it. You can't get that money back either.